(Number of days with AQI values greater than 100 at trend sites and all monitoring sites)

Metropolitan
Statistical Area

All sites

Trend sites

(R) Total number of sites in 2010

(R)
Number of days with AQI > 100 (2010)

(R) Number of trend
sites

Number of days with AQI >
100

1994

1995

1996

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

2010

Akron,
OH

18

4

7

69

49

66

72

73

83

52

71

82

57

60

62

34

23

8

0

4

Albany-Schenectady-Troy,
NY

26

4

7

13

12

9

8

9

15

(R) 4

18

(R) 18

(R) 10

5

(R) 9

(R) 3

(R) 15

(R) 8

1

4

Albuquerque,
NM

77

2

15

5

4

5

2

3

6

8

2

11

15

5

9

3

1

0

0

1

Allentown-Bethlehem-Easton,
PA

28

18

5

17

18

19

23

39

32

16

34

38

14

13

18

10

12

10

1

12

Atlanta-Sandy
Springs-Marietta, GA

64

27

17

35

57

50

61

84

97

72

42

44

24

22

32

46

40

25

11

14

Austin-Round
Rock, TX

25

3

1

8

28

5

2

9

14

14

5

8

9

8

9

13

4

2

4

2

Bakersfield,
CA

57

84

14

129

133

127

94

104

(R) 158

(R) 162

158

(R) 185

(R) 165

(R) 159

(R) 119

137

(R) 129

(R) 145

123

84

Baltimore-Towson,
MD

73

33

16

62

57

43

46

70

55

37

50

59

30

31

36

33

45

23

11

33

Baton
Rouge, LA

53

33

18

50

60

44

56

52

61

72

39

49

43

54

90

48

44

31

28

25

Bergen-Passaic,
NJ

20

22

6

0

0

0

0

1

2

1

1

1

2

1

4

2

1

U

U

U

Birmingham-Hoover,
AL

60

15

21

37

50

26

30

40

71

89

44

28

31

17

37

36

41

12

5

13

Boston-Cambridge-Quincy,
MA-NH

125

5

15

10

1

2

1

3

(R) 8

0

4

(R) 11

8

1

4

1

3

0

0

1

Bradenton-Sarasota-Venice,
FL

29

2

3

7

6

3

14

15

(R) 10

16

14

3

10

18

11

5

4

5

1

1

Bridgeport-Stamford-Norwalk,
CT

38

17

10

39

28

22

31

37

29

22

33

41

19

11

25

21

27

19

5

17

Buffalo-Niagara
Falls, NY

41

3

9

(R) 14

(R) 13

(R) 10

(R) 7

(R) 27

(R) 22

(R) 11

(R) 27

(R) 29

(R) 13

(R) 8

(R) 23

(R) 7

(R) 27

4

1

2

Charleston-North
Charleston, SC

28

0

8

10

1

7

7

12

13

9

0

4

3

3

8

9

5

1

0

0

Charlotte-Gastonia-Concord,
NC-SC

52

14

7

15

32

40

41

67

62

38

31

41

12

16

25

21

33

16

2

14

Chicago-Naperville-Joliet,
IL-IN-WI

231

28

59

69

80

47

57

84

81

51

86

46

37

28

53

28

52

46

24

28

Cincinnati-Middletown,
OH-KY-IN

109

27

20

(R) 37

(R) 39

(R) 36

(R) 31

(R) 44

(R) 52

(R) 28

(R) 39

(R) 47

(R) 28

(R) 16

(R) 41

(R) 19

(R) 42

14

5

16

Cleveland-Elyria-Mentor,
OH

91

73

24

153

116

109

80

94

120

61

62

86

72

62

89

64

60

54

3

16

Columbia,
SC

43

9

7

11

15

23

28

45

37

26

24

23

14

17

22

18

14

14

3

9

Columbus,
OH

32

6

7

23

27

26

17

40

37

16

20

38

12

3

20

5

13

4

1

2

Dallas-Fort
Worth-Arlington, TX

135

18

10

56

60

35

47

58

41

54

43

40

40

32

56

39

16

20

19

11

Dayton,
OH

23

13

4

12

10

17

11

9

17

3

8

19

2

0

10

1

3

0

1

1

Denver-Aurora,
CO

88

11

17

31

17

24

20

22

11

15

19

15

23

4

10

21

16

4

4

4

Detroit-Warren-Livonia,
MI

75

23

22

31

37

43

29

50

72

38

58

54

37

37

62

38

35

24

9

23

El
Paso, TX

63

9

13

49

72

61

27

33

8

16

14

15

13

5

10

10

8

8

2

3

Fort
Lauderdale, FL

36

7

12

3

3

2

3

9

7

5

5

3

0

1

1

4

7

U

U

U

Fort
Worth-Arlington, TX

37

21

6

53

52

28

27

32

33

38

31

37

38

25

43

34

12

U

U

U

Fresno,
CA

41

62

20

90

91

105

118

86

164

164

186

204

167

84

95

97

93

89

80

62

Gary,
IN

63

16

16

12

30

17

15

22

33

18

45

27

15

8

19

3

11

U

U

U

Grand
Rapids-Wyoming, MI

13

2

6

14

15

11

9

4

(R) 11

6

(R) 16

17

10

3

16

(R) 8

8

1

1

1

Greensboro-Winston
Salem-High Point, NC

62

39

5

20

25

18

30

48

38

29

22

42

13

5

14

8

21

U

U

U

Greenville-Mauldin-Easley,
SC

26

3

5

3

15

17

13

18

36

20

24

28

7

2

11

10

8

6

0

1

Harrisburg-Carlisle,
PA

16

5

8

33

33

18

23

38

33

19

42

37

16

10

22

14

20

13

0

4

Hartford-West
Hartford-East Hartford, CT

35

9

6

25

28

14

19

26

26

14

27

34

13

11

19

15

24

10

3

9

Honolulu,
HI

31

0

9

0

0

0

0

1

1

2

2

1

2

2

2

1

0

0

0

0

Houston-Sugarland-Baytown,
TX

128

34

25

66

92

56

67

65

74

69

50

44

55

42

58

35

28

18

18

21

Indianapolis-Carmel,
IN

90

15

19

(R) 60

(R) 48

(R) 36

(R) 30

(R) 40

(R) 45

(R) 25

(R) 33

(R) 48

(R) 32

(R) 20

(R) 48

(R) 25

(R) 33

7

6

8

Jacksonville,
FL

33

16

12

53

25

26

26

41

34

59

38

57

8

15

20

34

15

10

3

15

Jersey
City, NJ

17

14

8

19

21

15

20

16

28

9

17

22

10

5

13

13

12

U

U

U

Kansas
City, MO-KS

86

25

13

19

36

15

20

23

13

21

9

26

45

33

42

65

34

36

41

18

Knoxville,
TN

53

16

17

53

82

87

82

109

126

97

86

118

96

98

101

84

107

80

20

15

Las
Vegas-Paradise, NV

100

10

3

(R) 7

(R) 3

(R) 12

(R) 2

(R) 7

8

(R) 4

(R) 1

(R) 8

10

4

8

(R) 9

(R) 5

0

0

1

Little
Rock-North Little Rock-Conway, AR

30

2

8

8

24

9

10

13

16

29

17

18

3

0

19

11

11

2

2

2

Los
Angeles-Long Beach-Santa Ana, CA

169

79

50

200

178

141

117

93

(R) 140

119

(R) 130

110

120

106

65

(R) 62

60

68

54

37

Louisville/Jefferson
County, KY-IN

62

54

14

89

69

58

59

79

110

73

79

62

58

54

71

51

75

44

25

29

Madison,
WI

18

2

3

1

15

7

5

8

12

3

7

10

8

1

9

1

10

1

0

2

McAllen-Edinburg-Mission,
TX

8

0

1

0

0

0

0

0

0

0

0

0

2

0

0

0

0

0

0

0

Memphis,
TN-AR-MS

49

14

9

37

56

(R) 38

35

55

56

52

33

34

29

11

(R) 36

30

(R) 33

10

4

13

Miami-Fort
Lauderdale-Pompano Beach, FL

91

4

24

16

16

9

9

14

20

18

8

5

4

11

4

11

10

5

2

3

Middlesex-Somerset-Hunterdon,
NJ

15

30

4

19

31

19

28

39

35

19

29

36

11

15

22

9

21

U

U

U

Milwaukee-Waukesha-West
Allis, WI

58

9

12

17

23

15

6

16

25

8

25

21

17

6

21

6

11

3

5

8

Minneapolis-St.
Paul-Bloomington, MN-WI

132

4

18

18

22

6

7

5

5

9

12

5

15

11

11

1

5

1

2

1

Monmouth-Ocean,
NJ

5

21

4

41

34

31

32

46

35

19

35

46

25

22

27

19

21

U

U

U

Nashville-Davidson-Murfreesboro-Franklin,
TN

51

10

17

(R) 32

(R) 49

(R) 46

(R) 50

(R) 46

(R) 73

(R) 48

(R) 24

(R) 34

20

7

(R) 29

17

34

9

1

9

Nassau-Suffolk,
NY

22

16

5

28

20

14

23

27

28

12

14

22

15

6

19

11

14

U

U

U

New
Haven-Milford, CT

50

10

7

19

23

15

25

15

22

18

22

32

17

6

19

8

13

9

1

8

New
Orleans-Metairie-Kenner, LA

61

66

7

12

33

11

15

17

35

29

18

4

15

12

13

13

17

2

6

8

New
York-Northern New Jersey-Long Island, NY-NJ-PA

268

37

53

(R) 68

(R) 48

(R) 51

(R) 52

(R) 62

(R) 57

(R) 39

(R) 56

(R) 62

(R) 37

(R) 38

(R) 46

(R) 39

39

29

11

31

Newark,
NJ

44

21

16

33

33

24

23

35

36

17

34

43

14

8

18

25

21

U

U

U

Oakland,
CA

86

7

19

5

13

9

2

11

20

12

15

23

13

8

6

13

5

U

U

U

Oklahoma
City, OK

36

3

8

21

29

10

15

36

17

16

24

10

13

6

12

31

4

4

5

2

Omaha-Council
Bluffs, NE-IA

41

3

11

1

3

0

1

3

5

3

2

0

1

1

1

0

1

0

1

1

Orange
County, CA

30

19

8

30

20

13

8

7

7

11

6

6

15

10

0

7

9

U

U

U

Orlando-Kissimmee,
FL

28

2

13

7

9

6

6

23

13

15

13

5

4

5

8

8

8

1

0

1

Oxnard-Thousands
Oaks-Ventura, CA

38

13

14

100

103

98

76

54

54

57

52

26

48

41

36

31

22

30

24

10

Philadelphia-Camden-Wilmington,
PA-NJ-DE-MD

143

32

47

117

125

(R) 100

105

101

99

60

90

97

(R) 76

38

59

53

45

29

7

30

Phoenix-Mesa-Scottsdale,
AZ

165

43

23

33

41

47

33

49

52

46

25

22

26

9

23

25

11

11

6

10

Pittsburgh,
PA

128

64

38

(R) 175

(R) 117

(R) 118

(R) 143

(R) 151

(R) 150

(R) 121

(R) 111

131

(R) 115

94

(R) 94

(R) 67

(R) 77

60

43

42

Portland-Vancouver-Beaverton,
OR-WA

70

1

9

4

4

12

0

9

5

5

4

7

2

4

4

2

5

3

5

1

Poughkeepsie-Newburgh-Middleton,
NY

8

4

2

12

14

14

10

16

18

7

17

16

5

4

6

1

11

5

1

4

Providence-New
Bedford-Fall River, RI-MA

63

14

5

28

20

22

24

21

23

24

34

38

18

10

20

15

14

4

1

13

Raleigh-Cary,
NC

41

3

3

11

10

13

29

46

43

15

11

39

8

3

12

7

17

5

0

2

Richmond,
VA

38

11

9

39

33

37

45

54

41

20

27

46

19

12

29

17

24

17

1

7

Riverside-San
Bernardino-Ontario, CA

169

116

44

183

190

169

145

131

166

176

188

177

160

148

141

128

135

124

110

109

Rochester,
NY

17

0

1

8

10

1

10

11

17

2

14

16

5

0

0

1

5

2

0

0

Sacramento-Arden-Arcade-Roseville,
CA

112

24

22

71

61

70

39

56

94

65

72

90

67

56

58

74

40

45

29

14

St, Louis, MO-IL

164

86

28

(R) 138

(R) 146

(R) 121

(R) 99

(R) 92

(R) 106

(R) 77

(R) 81

(R) 85

(R) 65

(R) 33

(R) 72

(R) 28

(R) 35

21

9

19

Salt
Lake City, UT

49

17

9

30

8

18

4

21

18

(R) 21

30

(R) 32

(R) 19

36

26

20

27

17

16

17

San
Antonio, TX

41

4

2

7

32

7

10

12

20

5

4

26

18

6

10

8

3

7

3

3

San
Diego-Carlsbad-San Marcos, CA

65

15

23

97

103

62

44

53

53

58

53

35

41

27

26

39

33

35

25

14

San
Francisco-Oakland-Fremont, CA

115

4

33

8

14

13

4

15

21

17

19

26

13

10

6

19

5

12

4

4

San
Jose-Sunnyvale-Santa Clara, CA

44

8

5

13

21

37

7

21

14

9

9

24

14

7

4

13

3

13

6

6

San
Juan-Caguas-Guaynabo, PR

51

2

6

89

6

2

2

1

4

0

2

1

1

1

1

0

1

0

0

0

Scranton-Wilkes
Barre, PA

19

3

10

22

26

25

19

26

25

7

23

30

6

4

12

4

7

5

0

3

Seattle-Tacoma-Bellevue,
WA

120

1

10

3

3

5

0

6

6

17

12

13

10

4

6

10

9

7

8

0

Springfield,
MA

43

6

10

40

18

8

22

24

20

9

29

24

13

9

17

12

21

10

6

6

Stockton,
CA

16

5

5

10

12

7

2

19

23

14

11

13

6

3

5

16

11

10

4

2

Syracuse,
NY

19

3

5

8

10

3

6

10

12

2

13

19

4

0

8

3

8

3

1

3

Tacoma,
WA

25

14

4

3

3

4

0

6

2

15

11

9

8

4

4

9

7

U

U

U

Tampa-St.
Petersburg-Clearwater, FL

80

12

21

(R) 160

(R) 100

115

(R) 118

(R) 129

(R) 125

(R) 100

(R) 93

(R) 80

(R) 68

(R) 36

30

(R) 19

(R) 26

10

6

1

Toledo,
OH

20

4

3

(R) 11

(R) 14

(R) 14

(R) 7

(R) 8

(R) 16

(R) 9

(R) 21

(R) 21

(R) 14

(R) 6

(R) 19

(R) 2

(R) 4

1

2

4

Tucson,
AZ

52

0

20

10

14

8

8

7

8

5

0

7

7

0

8

9

1

2

2

0

Tulsa,
OK

40

3

8

27

40

27

15

27

30

23

31

22

16

9

22

24

4

13

2

3

Ventura,
CA

38

23

14

97

100

95

75

54

54

57

52

26

47

41

36

31

22

U

U

U

Virginia
Beach-Norfolk-Newport News, VA-NC

42

7

7

22

26

15

43

36

35

25

14

33

10

6

12

13

11

16

0

4

Washington-Arlington-Alexandria,
DC-MD-VA-WV

127

35

36

50

57

41

56

72

66

38

46

58

29

25

40

32

37

16

4

22

West
Palm Beach-Boca Raton, FL

24

3

4

0

0

0

0

0

0

1

0

0

0

0

0

0

2

U

U

U

Wichita,
KS

22

4

9

1

7

3

8

12

9

9

20

10

7

1

4

2

0

1

2

2

Wilmington-Newark,
DE-MD

41

27

9

46

47

22

31

42

40

24

36

34

24

10

22

20

25

U

U

U

Worcester,
MA

22

3

2

20

15

2

8

14

14

4

9

15

9

3

8

5

20

8

4

3

Youngstown-Warren-Boardman, OH

26

6

11

27

19

23

19

46

24

12

45

35

16

7

26

8

18

8

2

4

KEY: AQI =
Air Quality Index; R = revised.

NOTES

The Air Quality Index
(AQI) integrates information on 6 major pollutants (particulate matter less
than 10 microns in diameter, particulate matter less than 2.5 microns in
diameter, sulfur dioxide, carbon monoxide, ozone, and nitrogen dioxide)
across an entire monitoring network into a single number that represents the
worst daily air quality experienced in an urban area. An AQI greater than 100
indicates that at least 1 criteria pollutant exceeded air quality standards
on a given day; therefore, air quality would be in the unhealthful range on
that day. Air quality monitoring sites
are selected as "trend sites" if they have complete data for at
least 8 of the 10 last years.

The major reason for
revisions to the historical data for the AQI is that changes in the National
Ambient Air Quality Standards (NAAQS) are retroactively applied to the data
for previous years to provide consistent comparisons over time. In addition,
data from monitoring stations that have fallen below/surpassed the criterion
to qualify as a 'trend site' is excluded/included in the latest calculation
of the index.